KTNB-1205: Extract widget factory management into WidgetFactoryRegistry for improved modularity.

Author: ileasile

integrations/widgets/widgets-api/src/main/kotlin/org/jetbrains/kotlinx/jupyter/widget/WidgetManager.kt

@@ -15,8 +15,8 @@ import org.jetbrains.kotlinx.jupyter.api.libraries.CommManager
 import org.jetbrains.kotlinx.jupyter.widget.model.DEFAULT_MAJOR_VERSION
 import org.jetbrains.kotlinx.jupyter.widget.model.DEFAULT_MINOR_VERSION
 import org.jetbrains.kotlinx.jupyter.widget.model.DefaultWidgetModel
+import org.jetbrains.kotlinx.jupyter.widget.model.WidgetFactoryRegistry
 import org.jetbrains.kotlinx.jupyter.widget.model.WidgetModel
-import org.jetbrains.kotlinx.jupyter.widget.model.loadWidgetFactory
 import org.jetbrains.kotlinx.jupyter.widget.model.versionConstraintRegex
 import org.jetbrains.kotlinx.jupyter.widget.protocol.CustomMessage
 import org.jetbrains.kotlinx.jupyter.widget.protocol.RequestStateMessage
@@ -67,7 +67,7 @@ public class WidgetManager(
         commManager.registerCommTarget(widgetTarget) { comm, data, _, buffers ->
             val openMessage = Json.decodeFromJsonElement<WidgetOpenMessage>(data)
             val modelName = openMessage.state["_model_name"]?.jsonPrimitive?.content!!
-            val widgetFactory = loadWidgetFactory(modelName, classLoaderProvider())
+            val widgetFactory = WidgetFactoryRegistry.loadWidgetFactory(modelName, classLoaderProvider())
 
             val widget = widgetFactory.create()
             val patch = openMessage.toPatch(buffers)

integrations/widgets/widgets-api/src/main/kotlin/org/jetbrains/kotlinx/jupyter/widget/model/ModelCreation.kt

@@ -1,22 +1,8 @@
 package org.jetbrains.kotlinx.jupyter.widget.model
 
 import org.jetbrains.kotlinx.jupyter.widget.WidgetManager
-import java.util.ServiceLoader
-import java.util.concurrent.ConcurrentHashMap
 import kotlin.reflect.KClass
 
-private val factoryCache = ConcurrentHashMap<String, WidgetFactory<*>>()
-
-internal fun loadWidgetFactory(
-    modelName: String,
-    classLoader: ClassLoader,
-): WidgetFactory<*> =
-    factoryCache.getOrPut(modelName) {
-        ServiceLoader
-            .load(WidgetFactory::class.java, classLoader)
-            .firstOrNull { it.spec.modelName == modelName } ?: error("No factory for model $modelName")
-    }
-
 public fun <M : WidgetModel> WidgetManager.createAndRegisterWidget(widgetFactory: () -> M): M =
     widgetFactory().also { widget -> registerWidget(widget) }
 

integrations/widgets/widgets-api/src/main/kotlin/org/jetbrains/kotlinx/jupyter/widget/model/WidgetFactoryRegistry.kt

@@ -0,0 +1,22 @@
+package org.jetbrains.kotlinx.jupyter.widget.model
+
+import java.util.ServiceLoader
+import java.util.concurrent.ConcurrentHashMap
+
+public object WidgetFactoryRegistry {
+    private val factoryCache = ConcurrentHashMap<String, WidgetFactory<*>>()
+
+    internal fun loadWidgetFactory(
+        modelName: String,
+        classLoader: ClassLoader,
+    ): WidgetFactory<*> =
+        factoryCache.getOrPut(modelName) {
+            ServiceLoader
+                .load(WidgetFactory::class.java, classLoader)
+                .firstOrNull { it.spec.modelName == modelName } ?: error("No factory for model $modelName")
+        }
+
+    public fun registerWidgetFactory(factory: WidgetFactory<*>) {
+        factoryCache[factory.spec.modelName] = factory
+    }
+}